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Date: | Wed, 1 May 2002 18:43:29 -0400 |
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For those _really_ interested in cowries, I have explored the
range of possible labial tooth counts for a few of the Indo-
Pacific species of Cypraea with breeding populations in Hawaii.
By using the average labial tooth count and its standard deviation
from each of these four species, I have “inflated” their populations
to determine how big it would need to find a cowry with a labial
tooth count greater or smaller than the current range of labial teeth
in the samples that I am working with. A small table of possibilities
looks like this:
my range of # shells in (“new” popul.) to get 1
Cypraea lab. teeth my sample # of shells shell w/
helvola 11-20 2,600+ 10,000 10 or 21 th
fimbriata 17-26 500 1,150 16 labial th
caputserpentis 13-22 300 5,000 12 labial th
poraria 15-23 90 450 14 labial th
So, to have a definite shot at finding a _Cypraea helvola_ with
either 10 or 21 labial teeth, the chances are about one in ten
thousand. (Yes, just like a lottery, or something.) To get one
of 10 labial teeth AND one of 21 labial teeth, the sample would
need to be nearly 20,000 shells! (That is, in Hawaii; populations
in your area may vary.)
Perhaps others have stats from cowries in their locales...
Aloha,
makuabob (a.k.a. Bob Dayle)
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